European Union Law - General Principles

General Principles

The principles of European Union law are rules of law which have been developed by the European Court of Justice that constitute unwritten rules which are not expressly provided for in the treaties but which affect how European Union law is interpreted and applies. In formulating these principles, the courts have drawn on a variety of sources, including: public international law and legal doctrines and principles present in the legal systems of European Union member states and in the jurisprudence of the European Court of Human Rights. Accepted general principles of European Union Law include fundamental rights (see human rights), proportionality, legal certainty, equality before the law and subsidiarity.

Proportionality is recognised one of the general principles of European Union law by the European Court of Justice since the 1950s. According to the general principle of proportionality the lawfulness of an action depends on whether it was appropriate and necessary in order to achieve the objectives legitimately pursued. When there is a choice between several appropriate measures the least onerous must be adopted, and any disadvantage caused must not be disproportionate to the aims pursued. The principle of proportionality is also recognised in Article 5 of the EC Treaty, stating that "any action by the Community shall not go beyond what is necessary to achieve the objectives of this Treaty".

The concept of legal certainty is recognised one of the general principles of European Union law by the European Court of Justice since the 1960s. It is an important general principle of international law and public law, which predates European Union law. As a general principle in European Union law it means that the law must be certain, in that it is clear and precise, and its legal implications foreseeable, specially when applied to financial obligations. The adoption of laws which will have legal effect in the European Union must have a proper legal basis. Legislation in member states which implements European Union law must be worded so that it is clearly understandable by those who are subject to the law. In European Union law the general principle of legal certainty prohibits Ex post facto laws, i.e. laws should not take effect before they are published. The doctrine of legitimate expectation, which has its roots in the principles of legal certainty and good faith, is also a central element of the general principle of legal certainty in European Union law. The legitimate expectation doctrine holds that and that "those who act in good faith on the basis of law as it is or seems to be should not be frustrated in their expectations".